Carbon Nanotube Transistors through DNA Origami

Caltech researchers have applied DNA-based self-assembly to bind pairs of carbon nanotubes into structures that can act as field-effect transistors. Nature Nanotechnology has a prepublication release of their paper, “Self-assembly of carbon nanotubes into two-dimensional geometries using DNA origami templates”; the work emerged from a collaboration centered on the Winfree lab. Physorg.com reports the story behind the work — and on the prospects ahead, quoting William Goddard:

“This is a scalable technology. That is, one can design the origami to construct complex logic units and to do this for thousands or millions or billions of units that self-assemble in parallel.”

This achievement is a milestone in framework-directed self assembly of composite nanosystems, a line of development that I’ve argued is a strategic direction in atomically precise fabrication — useful in itself, and as part of a technology platform for further progress. In self-assembling molecular machine systems, carbon nanotubes could serve as structural components that are orders of magnitude stiffer than biomolecules, and can also serve as moving parts, including low-friction linear and rotary bearings.

In recent months, I’ve discussed breakthroughs in extending DNA origami to 3D structures: a technique for folding origami sheets to form boxes and a more radical technique for making solid DNA nanostructures. To bind nanotubes to origami structures, the Caltech team wrapped them in single strand DNA, a self-assembly technique that can make the tubes soluble. As I reported earlier, techniques based on DNA wrapping have also been used to separate nanotubes of specific types from an as-synthesized mixture.

For perspective, remember that nanolithography working at a billion-device scale requires a set of large, expensive, extraordinarily precise machines; industrial-scale fabs now cost billions of dollars. You’ll see nothing like these machines in the Winfree lab, or in the production areas of other bionanotechnology labs. Atomically precise self assembly on a billion-device scale can be done using glassware, pipettes, heaters, freezers, and the like. From an equipment point of view, the harder part is seeing the result, but for reasonably flat structures, desktop-scale AFMs can do the job.

“…can make the tubes soluble and.” and what??? Don’t leave us hanging! I’m guessing “and able to bind to each other in precisely specified patterns.”

Seeing the result may be hard. But combine this transistor-building technique with IBM’s technique for fastening down DNA macrostructures, oriented, on lithographed spots, and you may be able to simply run JTAG tests. Eventually.

Between the work I am seeing on Graphene, and the work being done on DNA and nanotubes, it’s seeming possible that we’ll see a complete nano electronic circuit produced soon. Scaling seems to be progressing quite well.

It’s possible we’ll see the first nanoscale processors this decade, maybe even sooner.

@ John — Yes, the sizes are very different, and this limits the scope of any proper comparison. There is, however, a fundamental similarity (both do nanoscale fabrication) paired with a great contrast in the nature of the equipment. Comparing these illustrates something important.

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Thank you for the useful post on Carbon Nanotube Transistors through DNA Origami.